Method of and means for reducing the viscosity of liquids



Nov. 6, 1928.

- E. A. sNow METHOD OF AND MEANS FOR REDUCING THE VISCOSITY 0F LIQUIDSFiled April 1927- Z w i 0 3% 6a a a h 7 v 5 y m a m, 1

m 7 d m J y, 4 7/ URL Patented Nov. 6, 1928.

UNITED STATES PATENT OFFICE.

EDWARD A. SNOW, OF READING, MASSACHUSETTS.

METHOD OF AND MEANS FOR REDUCING THE VISCOSITY OI LIQUIDS.

Application filed April 4,

mon practice to subject the mix to homogenizing effects preparatory tocooling, ageing and freezing in order that the product will be smoothand free from lumps, and'this part of the process is carried out by useof homogenizing apparatus including a pressure pump and one or morehomogenizing valves. In passing the mix through the valve or valves of ahomogenizing machine the constrictions provided by the valves, inconjunction with the friction and very high pressure under which the mixis forced through said constrictions, operate to break up all of thesolids such as butter fat, albumin, ash and the like, with the resultthat upon leaving the homogenizing machine or apparatus the mix is athoroughly homogenized emulsion, but it is also objectionablythick andviscous. From the homogenizing machine the mix has heretofore ordinarilybeen conducted through a conduit or pipe directly to the cooler, andowing to the viscous condition of the mix as it leaves the homogenizingapparatus and reaches the cooler, together with the further stiffeningor thickening effects produced by the cooler itself, it has resulted inso increasing the degree of viscosity of the mix as to often prevent,and always interfere more or less, with the flow thereof over and fromthe cooler and also often clogged the cooling apparatus and stopped itsoperation. By the use of my invention the viscosity of the mix as it istransferred from the homogenizer to the cooler is reduced to apredetermined degree such that free flow of thesame over and from thecooler is obtained. Furthermore, owing to the degree of fluidityestablished by use of this invention the mix flows over the coolerproperly and freely so that it does not freeze thereon and is morethoroughly and properly aerated and 'cooled than has heretofore beenpossible. In using homogenizing apparatus alone to prepare the mix forthe cooling operation it has heretofore been possible to control orregulate the viscosity of the homogenized mix onlyin the sense-that thehomogenizing act-ion of the machine changes the. condition of the mixfrom that of afreely flowing-liquid to a com paratively stiff thickviscous emulsion varying in degree of viscosity with the degree ofhomogenizing action effected by the machine.

- after pointed out.

1927. Serial N0. 180,980.

Therefore, when the mix was very thoroughly homogenized it wasnecessarily rendered ob-' ect10nably thick and viscous.

My invention contemplates providing the otftake conduit into which themix is dehvered from a homogenizing apparatus, with a constriction soproportioned as to capacity that the back pressure produced by the sameis less than an effective homogenizing pres-- sure. That is to say, thisconstriction is so regulated as to capacity that while the initial orhomogemzmg pressure may be, and herein 1s, utilized to propel thehomogenized mix through this. new constriction yet the back pressurecreated by this constriction is less than the pressure required toproduce homogenizing effects at this constriction. For example,homogenizing pressures are in the neighborhood of two or three thousandpounds per square inch, at least, whereas this constriction that Iprovide in the offtake pipe condult 1s proportioned or regulated so thatonly about one hundred pounds back pressure is created thereby. I findthat by passmg a viscous liquid through a constriction of this sortunder a pressure less than that required to produce homogenizing ordisintegrating effects, the viscosity of said liquid is reduced and thatthe'degree of reduction can be varied by varying the capacity of.

this constriction; In other words, the distinguishing feature of myinvention resides I in the employment of a constriction through isde-viscidified so to speak. I have also' found that while thehomogenizing process is best carried out under temperatures ranging fromFah., to Fah., bestresults are secured in connect-ion with theemployment of this feature of my invention by subjecting the liquid tothis viscosity reducing treatment at a temperature of 110 degrees Fah.,approximately or thereabouts, or the same as thatof the mix as it leavesthe homogenizing machine.

the-r features of my invention are herein- In the accompanying drawings:F gure 1 1s a diagrammatic view of a homogenizmg apparatus or machinehaving associated therewith an apparatus containing the presentinvention.

Figure 2 is a detail herelnafter described. Having reference to thedrawings 1 repre strap 3 with a sents a shaft provided with one ormore,'usually three, eccentrics 2,'each connected by a der 5. This, orthese, cylinders 5 communicate with a chamber 6 havin an inlet 7,controlled by a check valve 8, an connecting with a conduit 9 throughwhich the untreated ice cream mix or the like is supplied to the ma--'duit 18 with the inlet chine. The chamber 6 is also provided with anoutlet 10 controlled by a check valve '11,

, said outlet delivering to a chamber 12 conglobe valve fitting 19 whoseoutlet port is concontact with its nected by a conduit 20 with thecooler, or other destination of the mixor liquid. The fitting 19includes an interior partition 21 formed with a port 22 and a seat 23for a flat valve 24 by means of which the capacity of the port 22 isdetermined and regulated. The valve 24 is rotatably connected with theinner .end of a stem 25 having threaded engagement with the valve casingof fitting 19 so that by rotation thereof: the valve 24 may be adjustedtoward and from its seat 23 to regulate the capacity of the port 22whereby the proper operating conditions may be established. At its outerend the stem 25 maybe provided with a handle 26 through which the valve24 is manually adjusted or set. The conduit 18 communicates with abranch nipple 27 connected at its outer end with a T 28 whose oppositeport is connected by a nipple 29, elggw 30 and stop cock 31 with apressure gauge The valve 24 is ordinarily set just out of seat 23 andthe homogenized liquld, impelled by the homogenizing pressure, is forcedthrough the constricted assage thus provided between the valve an itsseat and the efl'ect of the combined velocity and attenuation of theliquid established and efi'ected by this constriction is to thin out theJmix, that is, the liquid is de-viscosed or, in

other words, its viscosity is reduced to the desired degree of fluidity.I

The valve 24 is properly'positionedby making use of the gauge 32 and isgradually closed while the homogenizing machine isin operation until theback valve builds up in itlhrpd pounds as indicated by the gauge 32, and

s said valve. at which it is left set.' As a safe guard againstsubjecting the gauge 32 to inurious p from the conduit 18 a safetypressure created by the piston 4 operating in a cylin the conduit 18 toone hunwill be the usual operative position for adapted to valve 33 isprovided that is connected with the T 28. This safety valve 33 may be ofstandard construction provided witha nipple 34 to be screwed into the T28 and with an outlet 35, the inlet 34 and outlet 35 being normally cutoil one from the other by a valve 36 held normally closed on its seat bya spring 37. The abutment ion the upper end of this spring 37 is a screw38 by means of which the efi'ective pressure of the spring 37 may beestablished as desired. In practice the abutment 38 is adjusted so thatthe valve 36 opens under a pressure of say three hundred pounds.

The stop cock 31 is provided as, means whereby communication between thegauge 32 and the conduit 18 may be so adjusted or regulated that thepulsating pressure within the conduit 18 dueto the reciprocatorymovements of the piston 4 will not vibrate the hand 39 of the gauge 32.That is, by partially closing' the stop cock 31 the movements of thepiston 4 are prevented from vibrating the hand39 and at the same timethe latter is free to be adjusted by the pressure within the conthecoagulated liquid through a conduit con-' taining a liquid acceleratingconstriction, by a pressure insufiicient to produce homogenizingeflects.

2. The method of preparing ice cream mix which consists in forcing thesame through a homogenizing valve by a pressure sufiicient to securehomogenizing effects and thereafter reducing the viscosity of thehomogenizing mix by passing the same through a'constriction under apressure less than the homogenizing pressure.

3. The combination of a valve fitting whose inlet is adapted to beconnected with a supply of coagulated liquid under pressure and having anormally unyielding valve ada ted .to be adjusted and set'so as tomaintain a relatively low pressureupon. the inlet side thereof that isless than a presure sufiicient to eflect homogenizing action, and aressure gauge connected with'the inlet of said valve ttin 4. Thecombination of a valve fittinlg having an inlet adapted to be connectedwit a supply of coagulated liquid under pressure and including anormally unyielding valve constriction that creates a back pressure lessthan that sufiicient to effect homogenization;

be adjusted and set to provide 'a a pressure gauge connected with theinlet of said valve fitting, and a safety valve connected with the inletof said fitting and operating automatically to open under a relativelylow pressure less than that suflicient to effect homogenization.

5. The combination with a pressure pump;

a homogenizing valve whose inlet is connected with the outlet of saidpum a conduit connected with the outlet of sai homogenizing valve and aliquid viscosity reducing constriction in said conduit which creates anonhomogenizing back pressure less than the homo enizing pressure ofsaid pump.

6. Zn apparatus constructed in accordance with claim 5 and including apressure gau e connected with said conduit between t e ho rznoienizingvalve and said constriction.

n apparatus of the character described constructed in accordance withclaim 5 and including a safety valve connected with said conduit betweensaid homogenizing valve and said constriction operating automatically toopen under aback pressure greater than is suflicient to reduce theviscosity of the liquid discharged into said conduit from saidhomogenizing valve. a

8. An apparatus of the character described constructed in accordancewith claim 5 whereincluding an. automatically operated-relief valveconnected with said conduit between said homogenizing valve and saidconstriction.

and State of Massachusetts, this 9th day of March, 1927.

EDWARD A. SNOW.

Signed byine at Boston, county of Suffolk

